Method and apparatus for sucking up material from the bottom of a body of water

ABSTRACT

Material is sucked up from the bottom of a body of water through a suction pipe into a wholly submerged container. The container is filled with water to submerge and trim the container, and this water is pumped out to create the suction that raises the material and to balance the added weight of the material so that the container remains at a constant depth. Material is discharged in a stream of water upwardly from the bottom of the container, and water is simultaneously admitted to the ballast tanks to maintain the container submerged. The container is in the form of two conical frusta that open into each other and are traversed by a vertical shaft for the various conduits. The container for the material is centrally disposed and the ballast tanks are peripherally disposed.

United States Patent [191 Laarman [5 METHOD AND APPARATUS FOR SUCKING UPMATERIAL FROM THE BOTTOM OF A BODY OF WATER [75] Inventor: JohannesBertus Laarman,

Zwijndrecht, Netherlands [73] Assignee: N.V. IndustrieeleHandelscombinatie Holland, Rotterdam, Netherlands 22 Filed: Sept. 15,1972 211 p]. No.: 289,292

[30] Foreign Application Priority Data Sept. 23, 1971 Netherlands7113102 [52] US. Cl 37/58, 37/72, 37/195, 37/DIG. 8, 302/14 [51] Int. ClE02f 3/88 [58] Field of Search 37/56, 58, DIG. 8, 72,.

[56] References Cited I UNlTED STATES PATENTS 3,260,004 7/1966 Brooks37/DlG. 8 3,415,068 12/1968 Casey, Jr. et al. 37/56 X 3,591,936 7/1971Van Geuns 37/56 June 11, 1974 3,593,533 7/1971 Washington 37/56 X3,620,572 1 1/1971 Krutein 3,693,272 9/1972 Gariel 37/72 X PrimaryExaminer-Robert E. Pulirey Assistant Examiner-Clifford D. CrowderAttorney, Agent, or Firm-Young & Thompson [57] ABSTRACT Material issucked up from the bottom of a body of water through a suction pipe intoa wholly submerged container. The container is filled with water tosubmerge and trim the container, and this water is pumped Out to createthe suction that raises the material and to balance the added weight ofthe material so that the container remains at a constant depth. Materialis discharged in a stream of water upwardly from the bottom of thecontainer, and water is simultaneously admitted to the ballast tanks tomaintain the container submerged. The container is in the form of twoconical frusta that open into each other and are traversed by a verticalshaft for the various conduits.

The container for the material is centrally disposed and the ballasttanks are peripherally disposed.

8 Claims, 2' Drawing Figures PATENTEUJUN 1 1 I974 SHEHIOF 2 METHOD ANDAPPARATUS FOR SUCKING UP MATERIAL FROM THE BOTTOM OF A BODY OF WATERThis invention relates to methods and apparatus for sucking up materialfrom the bottom of a body of water with the aid of a suction pipe.

Known methods for sucking up submerged material with the aid ofself-filling and self-propelling hopper craft are uneconomical wheredeep sea dredging and great distancesare involved.

Therefore, the principal object of the present invention is to provideamethod and apparatus for sucking up in particular deeply submergedmaterial which often has to be carried over long distances as well.

This object is achieved by the method of the invention, in which thematerial is sucked up through the suction pipe into a wholly submergedcontainer and this container is then unloaded. This method makes itpossible for the suction apparatus proper to remain in one and the samearea for quite a time, because the container serves as a loading stationwith a buffer stock of the material sucked up from the bottom, fromwhich container the material can be carried off in hopper craft or thelike, while it is furthermore possible to operate in deeper water thanwas previously the case, because the head, that is, the verticaldistance the material must be sucked up, remains limited to the distancebetween the container and the bottom. o

This object is also achieved by the apparatus of the invention,comprising a container with a suction pipe attached to the same, whichis divided into at least one ballast compartment by walls, which ballastcompartment has supply and discharge openings for water, and a hopperspace for the sucked-up material from the bed of a body of water, whichis connected with the suction pipe and with the suction side of a pumpand can be connected with a delivery chamber which is connected on'oneside with a discharge pipe and is connected on the other side with thepressure side of a pump.

Both the suction pipe and the suction side of the pump areadvantageously connected with or in the vicinity of. the upper portionof the hopper space. In this manner, sucking up takes place through thehopper space on filling the hopper space, so that the pump will onlysuck up water and will not suck up a mixture of water and material fromthe bottom.

The pump is preferably disposed in a shaft extending through the hopperspace, while a connection passing through the wall of the shaft servesto connect the hopper space with the suction side of the pump. Thismakes it possible to draw a high vacuum, relative to the water aroundthe hopper craft, in the hopper space with the aid of the pump. In thisembodiment, the lower ends of the shaft and of the container can formthe boundary of the delivery space, and the discharge conduit connectedwith said space can extend through the shaft.

For the purpose of facilitating the discharge of the container, thedividing walls inside the container are so constructed that they have adownwardly tapered shape, so that in essence the container is dividedinto a funnel-shaped hopper compartment and a ballast compartmentextending about the same, the narrow end portion of the hoppercompartment having valve members for connecting the hopper space and thedelivery space. A passage can connect the delivery space and thedelivery side of the pump, in which passage openings are provided, whichopen into the delivery space underneath the valve members of the ballastcompartment.

On discharging the container, water is pumped through the latter passagethrough the delivery space and the discharge conduit. This water willmix with the flow of material coming from the hopper space through thevalve members and will carry the material along, so that no materialwill flow through the pump even on discharging the container. It is tobe understood that one and the same water pump can be used for loadingand discharging the container.

The shaft in the container preferably extends to the upper part of thecontainer over such a distance that the top of said shaft will remainabove the water surface under all conditions.

In order to maintain the container at a constant depth and well trimmed,it is provided that on filling a hopper space ballast water willsimultaneously be discharged, while on discharging the container,ballast water will be fed thereto. To this end, for example, depthgauges may be provided by which valves are operated in the supply anddischarge conduits of the ballast compartments. When the container isloaded, the weight of ballast water pumped out of said container willsimultaneously indicate what weight of material is sucked up from thebottom into said container; consequently the quantity of material suckedup from the bottom can be determined in a very simple manner.

The container preferably has the shape of a float, which in essence iscomprised by two frusta with their bases against one another, and ashaft projecting above them so that the container has little flowresistance and will be little affected by the swell.

Other objects, features and advantages of the present invention willbecome apparent from a consideration of the following specification,taken in connection with the accompanying drawings, in which:

FIG. I is a somewhat schematic cross-sectional view of a firstembodiment of apparatus according to the present invention; and I FIG. 2is a somewhat schematic cross-sectional view of a second embodiment ofthe invention.

Referring now to the drawings in greater detail, and first to theembodiment of FIG. I, there is shown apparatus according to theinvention in the submerged operative position. The apparatus comprises acontainer 1, which is comprised by two conical frusta disposed againstone another. The container I is divided into a hopper compartment 3 anda ballast compartment 4 by means of the conically downwardly taperingdividing wall 2. Through the center of the container 1 extends a shaft 5which projects from the container 1 such a distance that its top part 6is above the water level 7 under all conditions. The bottom 8 of theshaft 5 is somewhat above the bottom of container ll, so that theseparts form the boundary of a delivery space 9 which by means of thevalve members 10 can be connected with the hopper compartment 3. Adischarge conduit 11 for delivery space 9 extends up through the shaft5.

Suction pipe 12 is connected with a conduit 13 which extends throughshaft 5 and opens in the upper part of the hopper compartment 3. Nearthe top of the hopper compartment 3 a conduit 14 is connected to pump15.

An air vent 18 for the ballast compartment 4 and a cable 19 for swingingthe suction pipe 12 are also provided.

FIG. 2 shows another embodiment of the delivery space. In thisembodiment the delivery space comprises two passages 21 and 22 situateddirectly underneath the hopper compartment 20, which passages 21 and 22can be placed in communication with the hopper compartment 20 throughthe valves 23 and 24 respectively. Each of the passages 21 and 22 has inthis embodiment a connection (not shown) with the pressure side of thepump adjacent one end and a connection with the discharge pipe 26adjacent the other end. The shaft 25 has a downwardly tapering shape.

In operation, the container 1, which is initially buoyant, is towed tothe operational site with its ballast compartment 4 and hoppercompartment 3 only partially loaded or even entirely empty. Water isthen fed into the ballast compartment 4 and into the hopper compartment3 through inlet openings (not shown) and this causes the body 1 to sinkbelow the water level until a predetermined depth has been reached. Theposition of the container 1 is maintained by anchors (not shown), whilethe container can be displaced by winches (not shown). Subsequently thesuction pipe 12 is lowered to the bottom 16 and the pump is operated.The vacuum in the hopper compartment 3 thus produced causes material tobe sucked up from the bottom through the suction pipe 12 and the conduit13 into the hopper space 3, whereas the water carried along with saidmaterial is discharged through the conduit 1 .4 and thepump 15. Whilethe hopper compartment 3 is loaded, water is pumped up from the ballasttank 4, possibly with the aid of the samp pump 15 through a separateconduit (not shown), causing the container 1 to maintain its position ata constant depth below the water surface. The quantity of water pumpedup from the ballast compartment 4 is an indication of the quantity ofmaterial sucked up from the bottom and passed into the hoppercompartment 3.

While the container l is to be discharged, the water pump, eitherdirectly or through the annular passage 17 at the bottom of thecontainer, will cause water to be fed into the delivery compartment 21or 22 and 9 respectively, while the valve members 23 or 24 and M)respectively will be opened, causing the material from the hoppercompartments and 3 respectively to be passed upwardly through thedischarge pipe together with the flow of water, whereupon said materialmay be loaded into a hopper craft, for instance, which will carry saidmaterial to its destination.

It is to be noted that in this case the remaining part of the hoppercompartments 20 and 3 respectively is entirely sealed off, causing avacuum to be created therein and making it possible for the material toflow downwardly due to its own weight. It is to be understood that theconduits ll, 13 and 14 are provided with control valves.

From the foregoing disclosure, it will be evident that the initiallyrecited object of the present invention has been achieved.

Although the present invention has been described and illustrated inconnection with preferred embodiments, it is to be understood thatmodifications and variations may be resorted to without departing fromthe spirit of the invention, as those skilled in this art will readilyunderstand. Such modifications and variations are considered to bewithin the purview and scope of the present invention as defined by theappended claims.-

What is claimed is:

1. Apparatus for sucking up submerged material from the bottom of a bodyof water, comprising a suction pipe for said material, a submersiblecontainer into which said suction pipe discharges, said container havingat least one ballast'compartment and at least one hopper compartment forthe material to be sucked up, pump means to create in said hoppercompartment a pressure lower than the pressure outside said containerthereby to draw material into said hopper compartment through saidsuction pipe, means to raise said material from the bottom of saidhopper compartment, and a shaft extending from said container to abovethe surface of the water, said pump means being disposed in said shaft,-said shaft extending downwardly through said container to adjacent thebottom of said hopper compartment but being spaced above the bottom ofsaid hopper compartment thereby to provide discharge space for saidmaterial from said hopper compartment.

2. Apparatus for sucking up submerged material from the bottom of a bodyof water, comprising a suction pipe for said material, a submersiblecontainer into which said suction pipe discharges, said container havingat least one ballast compartment and at least one hopper compartment forthe material to be sucked up, pump means to create in said hoppercompartment a pressure lower than the pressure outside said containerthereby to draw material into said hopper compartment through saidsuction pipe, and means to raise said material from the bottom of saidhopper compartment, said at least one hopper compartment being disposedcentrally of said container and said at least one ballast compartmentsurrounding said at. least one hopper compartment, said at least onehopper compartment having downwardly converging side walls.

3. Apparatus as claimed in claim'2, said hopper compartment beingfrusto-conical,

4. Apparatus as claimed in claim 3, said at least one ballastcompartment being frusto-conical and having side walls that convergedownwardly.

5. A method of sucking up submerged material from the bottom of a bodyof water with the aid of a suction pipe, comprising wholly submerging acontainer for a material in said body of water at a distance above thebottom of the body of water, sucking up the material through saidsuction pipe into said container, then raising material from saidcontainer to above the surface of said body of water by passing a streamof water through a bottom portion of said container to entrain saidmaterial in said stream of water, moving said stream of water up toabove the surface of said body of water, and establishing verticallysuperposed compartments in said container in the upper of which saidmaterial is disposed, the lower of said compartments comprising saidbottom portion of said container through which said stream of waterpasses, said compartments communicating with each other during saidraising of material whereby water moving through said lower compartmentremoves said material from the bottom of said upper compartment.

6. A method as claimed in claim 5 in which said upper and lowercompartments are out of communication with each other when said materialis being introduced into said upper compartment.

7. Apparatus for sucking up submerged material from the bottom of a bodyof water, comprising a suction pipe for said material, a submersiblecontainer into which said suction pipe discharges, said container havingat least one ballast compartment and at least one hopper compartment forthe material to be sucked up, pump means to create in said hoppercompartment a pressure lower than the pressure outside said containerthereby to draw material into said hopper compartment through saidsuction pipe, means to raise said material fromthe bottom of said hoppercompartment, said raising means comprising a water pump and means forconveying a stream of water discharged by said pump past a lower portionof said hopper compartment to entrain said material and then upwardlyabove the surface of the body of water, said means for conveying astream of water past the lower portion of said hopper compartmentcomprising means defining a water passage beneath said hoppercompartment, and means for establishing communication between saidhopper compartment and said water compartment during discharge ofmaterial from said hopper compartment.

8. Apparatus as claimed in claim 7, and means for interruptingcommunication between said'hopper compartment and said water compartmentduring introduction of material into said hopper compartment.

1. Apparatus for sucking up submerged material from the bottom of a bodyof water, comprising a suction pipe for said material, a submersiblecontainer into which said suction pipe discharges, said container havingat least one ballast compartment and at least one hopper compartment forthe material to be sucked up, pump means to create in said hoppeRcompartment a pressure lower than the pressure outside said containerthereby to draw material into said hopper compartment through saidsuction pipe, means to raise said material from the bottom of saidhopper compartment, and a shaft extending from said container to abovethe surface of the water, said pump means being disposed in said shaft,said shaft extending downwardly through said container to adjacent thebottom of said hopper compartment but being spaced above the bottom ofsaid hopper compartment thereby to provide discharge space for saidmaterial from said hopper compartment.
 2. Apparatus for sucking upsubmerged material from the bottom of a body of water, comprising asuction pipe for said material, a submersible container into which saidsuction pipe discharges, said container having at least one ballastcompartment and at least one hopper compartment for the material to besucked up, pump means to create in said hopper compartment a pressurelower than the pressure outside said container thereby to draw materialinto said hopper compartment through said suction pipe, and means toraise said material from the bottom of said hopper compartment, said atleast one hopper compartment being disposed centrally of said containerand said at least one ballast compartment surrounding said at least onehopper compartment, said at least one hopper compartment havingdownwardly converging side walls.
 3. Apparatus as claimed in claim 2,said hopper compartment being frusto-conical.
 4. Apparatus as claimed inclaim 3, said at least one ballast compartment being frusto-conical andhaving side walls that converge downwardly.
 5. A method of sucking upsubmerged material from the bottom of a body of water with the aid of asuction pipe, comprising wholly submerging a container for a material insaid body of water at a distance above the bottom of the body of water,sucking up the material through said suction pipe into said container,then raising material from said container to above the surface of saidbody of water by passing a stream of water through a bottom portion ofsaid container to entrain said material in said stream of water, movingsaid stream of water up to above the surface of said body of water, andestablishing vertically superposed compartments in said container in theupper of which said material is disposed, the lower of said compartmentscomprising said bottom portion of said container through which saidstream of water passes, said compartments communicating with each otherduring said raising of material whereby water moving through said lowercompartment removes said material from the bottom of said uppercompartment.
 6. A method as claimed in claim 5 in which said upper andlower compartments are out of communication with each other when saidmaterial is being introduced into said upper compartment.
 7. Apparatusfor sucking up submerged material from the bottom of a body of water,comprising a suction pipe for said material, a submersible containerinto which said suction pipe discharges, said container having at leastone ballast compartment and at least one hopper compartment for thematerial to be sucked up, pump means to create in said hoppercompartment a pressure lower than the pressure outside said containerthereby to draw material into said hopper compartment through saidsuction pipe, means to raise said material from the bottom of saidhopper compartment, said raising means comprising a water pump and meansfor conveying a stream of water discharged by said pump past a lowerportion of said hopper compartment to entrain said material and thenupwardly above the surface of the body of water, said means forconveying a stream of water past the lower portion of said hoppercompartment comprising means defining a water passage beneath saidhopper compartment, and means for establishing communication betweensaid hopper compartment and said water compartment during discharge ofmaterial from said hopper compartment.
 8. Apparatus as claimed in claim7, and means for interrupting communication between said hoppercompartment and said water compartment during introduction of materialinto said hopper compartment.